- Email: [email protected]
592 POSITIVE CARDIAC INOTROPIC EFFECT OF ALBUMIN INFUSION IN RATS WITH CIRRHOSIS AND ASCITES: MOLECULAR MECHANISMS
POSTERS Conclusion: Autonomic dysfunction is also present in noncirrhotic portal hypertension group as in cirrhotics. It affects the natural course in these patients and has important prognostic implication. Further followup studies required to further elucidate this dysfunction. 590 ASSESSMENT OF SYSTEMIC ENDOTHELIAL FUNCTION IN PATIENTS WITH CIRRHOSIS: COMPARISON BETWEEN PERIPHERAL ARTERIAL TONOMETRY (PAT) AND BRACHIAL ARTERY VASODILATATION BY ULTRASOUND (BAUS) A. Berzigotti1,2,3 , S. Seijo1,3 , E. Reverter1,3 , J.G. Abraldes1,3 , J.C. Garc´ıa-Pagan ´ 1,3 , J. Bosch1,3 . 1 Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clinic, IDIBAPS, 2 Diagnostic Imaging Center (CDIC), Hospital Clinic, University of Barcelona, 3 CIBERehd, Barcelona, Spain E-mail: [email protected] Background and Aims: Brachial artery flow-mediated vasodilatation (FMD) by ultrasound (BAUS) is the gold-standard for assessing systemic endothelial function (SEF). It has been suggested that SEF might play a role in the pathophysiology of the complications of cirrhosis but there are insufficient studies in this field since FMD is time-consuming and operator-dependent. Peripheral arterial tonometry (PAT, Endopat2000, Itamar, Israel) is a new simple, non-invasive, operator-independent method to assess SEF. PAT uses finger transducers to sense continuously the pulse wave of finger arteries bilaterally. A cuff is applied to the test arm, and arterial occlusion is obtained by 5-minutes inflation (similarly to BAUS). Post-occlusion vasodilatation is computed by the system as reactive hyperaemia index (RHI), which integrates test arm reactivity corrected for control arm reactivity. We aimed at assessing whether PAT is technically feasible in patients with cirrhosis, and whether its results correlate with those of BAUS. Methods: In 30 patients (23 men, 55±10 yrs) with cirrhosis and portal hypertension (Child-score 7.9±2.4; HVPG 17.6±4.5 mmHg) we assessed SEF on the same day both by BAUS (FMD) and by PAT (RHI). According to previous reports, endothelial dysfunction was defined as FMD < 10% or RHI < 1.60. The correlation between the two methods and the concordance on presence or absence of endothelial dysfunction were assessed. Results: Both techniques had 100% applicability. FMD was 10.3±6.4% (median 9.8%, range 0–30.1%), and RHI was 2.15±0.71 (median 2.04, range 1.32–3.95). The correlation between FMD and RHI was significant, but moderate (R = 0.453, p = 0.012). Endothelial dysfunction was observed in 15 patients (50%) according to BAUS and in 7 (23.3%) according to PAT; concordance between the two methods was fair (k = 0.333, p = 0.031). RHI but not FMD showed an inverse correlation with the number of cardiovascular risk factors (R = −0.419, p = 0.02) and a direct correlation with mean arterial pressure (R = 0.431, p = 0.03), suggesting a better correlation with vascular function. On the other hand FMD, but not RHI, correlated with Child-score (R = 0.431, p = 0.01). Conclusions: The assessment of SEF by PAT is feasible in patients with cirrhosis, and its results correlate with presence of cardiovascular risk factors and systemic hemodynamics. PAT appears a promising method for overcoming the limitations of BAUS.
S240
591 PORTAL VEIN THROMBOSIS IN EGYPTIAN PATIENTS WITH LIVER CIRRHOSIS: ROLE OF METHYLENETETRAHYDROFOLATE REDUCTASE C677T GENE MUTATION S.S. Bessa1 , M.A. Gabr1 , E.A. El-Zamarani2 . 1 Department of Internal Medicine, 2 Department of Clinical Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt E-mail: [email protected] Aims: The pathogenesis of non-malignant portal vein thrombosis (PVT) in cirrhotic patients is not clearly defined. This case-control study aimed to investigate the role of methylenetetrahydrofolate reductase (MTHFR) C677T gene mutation in the pathogenesis of PVT in Egyptian cirrhotic patients. Methods: Plasma homocysteine was measured and MTHFR C677T gene mutation was detected in 76 cirrhotic patients (21 with PVT, 55 without PVT) and 20 healthy controls. Results: The frequency of CC genotype (wild type) in cirrhotic patients with PVT was lower than controls and cirrhotics without PVT. However, the frequency of TT genotype (homozygous mutation) was elevated in cirrhotic patients with PVT as compared to controls and those without PVT. Cirrhotic patients with PVT had significantly higher homocysteine than those without PVT. Cirrhotic patients with TT genotype are at a significant risk for PVT (odds ratio = 7.7, 95% confidence interval, 1.50–42.81) when compared with CC genotype. Moreover, subjects carrying TT genotype had a higher homocysteine than those carrying CC genotype. Conclusions: The TT genotype of MTHFR is associated with an increased risk of PVT in Egyptian cirrhotic patients. Hyperhomocysteinemia could be considered as a relatively new risk factor for PVT in cirrhotic patients and plasma homocysteine should be investigated particularly in patients with PVT of unexplained etiology. The important clinical implication is that the readily available therapy of folate, vitamin B6 and B12 supplementation may reduce homocysteine and prevent further thrombotic complications in cirrhotic patients carrying the TT genotype. 592 POSITIVE CARDIAC INOTROPIC EFFECT OF ALBUMIN INFUSION IN RATS WITH CIRRHOSIS AND ASCITES: MOLECULAR MECHANISMS A. Bortoluzzi1 , A. Sticca1 , G. Segato1 , G. Ceolotto1 , S. Bova2 , A. Gatta1 , P. Angeli1 . 1 Department of Clinical and Experimental Medicine, 2 Department of Pharmacology and Anaesthesiology, Universit` a degli Studi di Padova, Padova, Italy E-mail: [email protected] Background: There is no therapeutic option for systolic dysfunction in decompensated cirrhosis. Preliminary data showed that albumin infusion may improve cardiac contractility in a model of septic shock through an inhibitory action either on reactive oxygen species (ROS) or on the tumor necrosis factor (TNF)a-inducible nitric oxide synthase (iNOS) pathway. Aim: To evaluate the effect of albumin infusion on cardiac contractility in experimental cirrhosis with ascites and its possible molecular mechanism. Methods: 30 Wistar Kyoto rats with CCl-4-induced cirrhosis and ascites and 30 control rats were studied. For each groups, 15 rats have been treated with 40% solution of albumin, 15 with the same volume of saline. Isoproterenol-stimulated cardiac contractility was recorded in isolated hearts. Cardiac gene and protein expression of b2 adrenergic receptor signaling including an isoform of inhibitory G-protein (Gai2) and adenylate cyclase 3 (Adcy3) and of iNOS, and NAD(P)H-oxidase activity, a source of ROS, were obtained using real time PCR and Western Blot respectively. Serum level of TNF-a and NF-kB translocation into nucleus in cardiac tissue were analyzed with ELISA.
Journal of Hepatology 2011 vol. 54 | S209–S361
POSTERS Results: Baseline cardiac contractility was significantly reduced in rats with cirrhosis as compared to control rats (p < 0.01). This finding was associated with: (a) an higher serum level of TNF-a (p < 0.05), (b) an increased gene and protein expression of b2-AR (p < 0.05), of: Gai2 (p < 0.05), iNOS (p < 0.05), an increased NAD(P)Hoxidase activity (p < 0.05), (c) an increased nuclear translocation of NF-kB (p < 0.05) and (d) a lower expression of Adcy3 (p < 0.05) in cardiac tissue of rats with cirrhosis. After albumin infusion the cardiac contractility was completely recovered in rats with cirrhosis (p < 0.01). Protein expression of Gai2 (p < 0.05), iNOS (p < 0.05) and NAD(P)H-oxidase activity (p < 0.05) in the cardiac tissue of rats with cirrhosis were reversed to control levels. A significant decrease in serum level of TNF-a (p < 0.05) and in nuclear translocation of NF-kB in the cardiac tissue (p < 0.05) of cirrhotic rats was also observed. Conclusions: These results demonstrated that albumin exerts a positive cardiac inotropic effect in rats with cirrhosis and ascites This effect involves its capacity to counteract the negative effects on cardiac contractility of ROS- and TNF-a-induced NF-kB-iNOS pathway. 593 HEPATOPROTECTIVE AND ANTIHEPATOFIBROTIC EFFECTS OF YI GUAN JIAN IN RATS WITH DIMETHYLNITROSAMINE-INDUCED LIVER FIBROSIS J.Y. Chen1 , H.J. Lin2 , S.T. Kao2 , C.M. Chen1 . 1 Life Sciences, National Chung Hsing University, 2 School of Chinese Medicine, China Medical University, Taichung, Taiwan R.O.C. E-mail: [email protected] Background and Aims: Yi Guan Jian (YGJ) has long been employed clinically to treat liver fibrosis in traditional Chinese Medicine but the mechanism underlying the regulation has not been clarified in detail. The present investigation was designed to assess the involvement of the fibrosis pathway in dimethylnitrosamine (DMN)-induced liver fibrosis in rats and molecular mechanisms underlying prevention of liver fibrosis. Methods: Eighteen Sprague-Dawley rats were divided into three groups of six rats each, liver fibrosis was induced by DMN injection (10 mg kg−1 , ip, given three consecutive days each week) following 4 weeks. YGJ was oral administered (1.8 g kg−1 , op, daily for two weeks). Liver sample were subjected to histological and western bolt studies. For evaluation of hepatic fibrosis-related factors, collagen a1-I, tissue inhibitor of metalloproteinase-1 (TIMP-1), and a-smooth muscle actin (a-SMA) mRNA and protein levels were analyzed. The signaling of associated mechanisms were validated in vitro using HSC-T6 cell lines. Results: YGJ significantly attenuated the DMN-induced excessive level of GOT and GPT (p < 0.01) in serum, and hydroxyproline content in liver tissue (p < 0.001). Histophathological result revealed that YGJ markedly reduced collagen acumination and hepatic satellite cells activation. In gene expression analysis, YGJ down regulated fibrosis-related genes including TIMP-1, collagen a1-I and a-SMA in liver tissue. In protein level, YGJ reduced the a-SMA in liver tissue (p < 0.001). YGJ induced HSCs apoptosis concomitant with the down-regulation of Bcl-2 expression and slight elevation of Bax level. Moreover, the reactive oxygen species (ROS) were generated in the early stages of YGJ-induced HSCs apoptosis to facilitate calcium and cytochrome c release from the mitochondria to cytosol. Subsequently, caspase-9 and caspase-3 were activated. YGJ decoction induces HSCs apoptosis through ROS accumulation and the intrinsic apoptosis pathway. Conclusions: These results showed that YGJ has hepatoprotective and antihepatofibrotic effects against DMN-induced liver fibrosis. Its possible mechanisms are associated with HSCs apoptosis through ROS accumulation and down-regulation of the fibrogenic gene, especially TIMP-1, collagen a1-I and a-SMA.
594 THE EFFECT OF LITHIUM ON CARDIOVASCULAR SYMPTOMS IN CHOLESTATIC RATS A.R. Dehpour1 , M. Rahimi Balaei1 , R. Babaeikelishomi2 , S. Ejtemaei Mehr1 . 1 Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; 2 Department of Molecular Pharmacology, School of Medicine, University of Goettingen, Goettingen, Germany E-mail: [email protected] Background and Aims: Cholestatic liver disease is known for cardiac and renal complications. Short term (10 days) bile duct ligation (BDL) is a model for cholestasis studies. Lithium is widely used for treatment of neuropsychiatric symptoms in bipolar disorders. Recent studies indicate the cardioprotective effects of lithium in heart ischemia-reperfusion and anthracycline-induced injuries. The purpose of this study was to investigate lithium protective effect on heart in BDL rat model of cardiomyopathy. Methods: Male Wistar rats (200–230 g) were chosen and randomized in five groups; control, Li, Li+sham, BDL, Li+BDL. In Li+BDL group, they were treated with 300 mg/kg p.o. lithium in their water supply for three weeks and then for ten days after bile duct ligation. At the end of the experiment, ECG parameters and papillary muscle contractility force were assessed. Serum samples were collected for measurement of lithium concentrations. In addition, cardiac tissues were evaluated both macroscopically and microscopically. Results: We found that lithium can improve bradycardia induced in BDL rats, Sa -T segment, QT interval prolongations and heart contractility force. Also histopatologic findings showed lower cardiac lesions in Li+BDL group (by p < 0.05). Conclusion: All of these findings underline the protective effect of lithium in 10 days BDL rats. 595 BENEFICIAL EFFECT OF N-ACETYL-CYSTEINE ON HEPATIC ENCEPHALOPATHY: “IN VIVO” AND “IN VITRO” STUDY A. Dibenedetto1 , D. Donnini1 , L. Domenis1 , D. De Silvestri1 , D. Cappello1 , A. Carnelutti1 , L. Veriello2 , G. Pauletto2 , L. Sechi1 , G. Soardo1 . 1 Liver Unit, Department of Pathology and Experimental and Clinic Medicine, 2 Neurology Clinic, Department of Pathology and Experimental and Clinic Medicine, University of Udine, Udine, Italy E-mail: [email protected] Introduction: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome which causes severe morbidity in end-stage liver disease. Evidence identifies ammonia as the key factor in the pathogenesis of HE. Experimental animal models has been demonstrated that oxidative/nitrosative stress induces or aggravates astrocyte swelling with subsequent alterations of ammonia metabolism and glioneuronal communication. Aim of study: investigating the potential neuroprotective effects of antioxidant substance such as N-Acetylcysteine (NAC) on ecephalopathy status in a group of cirrhotic patients affected by recurrent episodes of HE and in “in vitro” system of U-87 astrocytes cell line, stimulated with ammonia. Methods: 15 encephalophatic cirrhotic patients (mean age 61.1 y) were studied. 10 patients were treated with conventional therapy plus 2,400 mg/day of NAC. 5 patients were a control group. At the time 0 and 30 we measured ammonia, oxidative stress markers levels: Nitric Oxide (NO), Malondyaldeide (MDA), Glutathione (GSH) and psychometric tests; serial-dotting-test (SDT), trail-making-test A and B (TMT-A, TMT-B). Astrocytes were incubated for 2 hours in absence or in presence of 5 mM of ammonia (NH4 ) with 0.2 mM of Gglutamate and with or without 5 mM of NAC and 2 mM of GSH. As markers of oxidative stress we measured the MDA extra-cellular levels.
Journal of Hepatology 2011 vol. 54 | S209–S361
S241
S240
591 PORTAL VEIN THROMBOSIS IN EGYPTIAN PATIENTS WITH LIVER CIRRHOSIS: ROLE OF METHYLENETETRAHYDROFOLATE REDUCTASE C677T GENE MUTATION S.S. Bessa1 , M.A. Gabr1 , E.A. El-Zamarani2 . 1 Department of Internal Medicine, 2 Department of Clinical Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt E-mail: [email protected] Aims: The pathogenesis of non-malignant portal vein thrombosis (PVT) in cirrhotic patients is not clearly defined. This case-control study aimed to investigate the role of methylenetetrahydrofolate reductase (MTHFR) C677T gene mutation in the pathogenesis of PVT in Egyptian cirrhotic patients. Methods: Plasma homocysteine was measured and MTHFR C677T gene mutation was detected in 76 cirrhotic patients (21 with PVT, 55 without PVT) and 20 healthy controls. Results: The frequency of CC genotype (wild type) in cirrhotic patients with PVT was lower than controls and cirrhotics without PVT. However, the frequency of TT genotype (homozygous mutation) was elevated in cirrhotic patients with PVT as compared to controls and those without PVT. Cirrhotic patients with PVT had significantly higher homocysteine than those without PVT. Cirrhotic patients with TT genotype are at a significant risk for PVT (odds ratio = 7.7, 95% confidence interval, 1.50–42.81) when compared with CC genotype. Moreover, subjects carrying TT genotype had a higher homocysteine than those carrying CC genotype. Conclusions: The TT genotype of MTHFR is associated with an increased risk of PVT in Egyptian cirrhotic patients. Hyperhomocysteinemia could be considered as a relatively new risk factor for PVT in cirrhotic patients and plasma homocysteine should be investigated particularly in patients with PVT of unexplained etiology. The important clinical implication is that the readily available therapy of folate, vitamin B6 and B12 supplementation may reduce homocysteine and prevent further thrombotic complications in cirrhotic patients carrying the TT genotype. 592 POSITIVE CARDIAC INOTROPIC EFFECT OF ALBUMIN INFUSION IN RATS WITH CIRRHOSIS AND ASCITES: MOLECULAR MECHANISMS A. Bortoluzzi1 , A. Sticca1 , G. Segato1 , G. Ceolotto1 , S. Bova2 , A. Gatta1 , P. Angeli1 . 1 Department of Clinical and Experimental Medicine, 2 Department of Pharmacology and Anaesthesiology, Universit` a degli Studi di Padova, Padova, Italy E-mail: [email protected] Background: There is no therapeutic option for systolic dysfunction in decompensated cirrhosis. Preliminary data showed that albumin infusion may improve cardiac contractility in a model of septic shock through an inhibitory action either on reactive oxygen species (ROS) or on the tumor necrosis factor (TNF)a-inducible nitric oxide synthase (iNOS) pathway. Aim: To evaluate the effect of albumin infusion on cardiac contractility in experimental cirrhosis with ascites and its possible molecular mechanism. Methods: 30 Wistar Kyoto rats with CCl-4-induced cirrhosis and ascites and 30 control rats were studied. For each groups, 15 rats have been treated with 40% solution of albumin, 15 with the same volume of saline. Isoproterenol-stimulated cardiac contractility was recorded in isolated hearts. Cardiac gene and protein expression of b2 adrenergic receptor signaling including an isoform of inhibitory G-protein (Gai2) and adenylate cyclase 3 (Adcy3) and of iNOS, and NAD(P)H-oxidase activity, a source of ROS, were obtained using real time PCR and Western Blot respectively. Serum level of TNF-a and NF-kB translocation into nucleus in cardiac tissue were analyzed with ELISA.
Journal of Hepatology 2011 vol. 54 | S209–S361
POSTERS Results: Baseline cardiac contractility was significantly reduced in rats with cirrhosis as compared to control rats (p < 0.01). This finding was associated with: (a) an higher serum level of TNF-a (p < 0.05), (b) an increased gene and protein expression of b2-AR (p < 0.05), of: Gai2 (p < 0.05), iNOS (p < 0.05), an increased NAD(P)Hoxidase activity (p < 0.05), (c) an increased nuclear translocation of NF-kB (p < 0.05) and (d) a lower expression of Adcy3 (p < 0.05) in cardiac tissue of rats with cirrhosis. After albumin infusion the cardiac contractility was completely recovered in rats with cirrhosis (p < 0.01). Protein expression of Gai2 (p < 0.05), iNOS (p < 0.05) and NAD(P)H-oxidase activity (p < 0.05) in the cardiac tissue of rats with cirrhosis were reversed to control levels. A significant decrease in serum level of TNF-a (p < 0.05) and in nuclear translocation of NF-kB in the cardiac tissue (p < 0.05) of cirrhotic rats was also observed. Conclusions: These results demonstrated that albumin exerts a positive cardiac inotropic effect in rats with cirrhosis and ascites This effect involves its capacity to counteract the negative effects on cardiac contractility of ROS- and TNF-a-induced NF-kB-iNOS pathway. 593 HEPATOPROTECTIVE AND ANTIHEPATOFIBROTIC EFFECTS OF YI GUAN JIAN IN RATS WITH DIMETHYLNITROSAMINE-INDUCED LIVER FIBROSIS J.Y. Chen1 , H.J. Lin2 , S.T. Kao2 , C.M. Chen1 . 1 Life Sciences, National Chung Hsing University, 2 School of Chinese Medicine, China Medical University, Taichung, Taiwan R.O.C. E-mail: [email protected] Background and Aims: Yi Guan Jian (YGJ) has long been employed clinically to treat liver fibrosis in traditional Chinese Medicine but the mechanism underlying the regulation has not been clarified in detail. The present investigation was designed to assess the involvement of the fibrosis pathway in dimethylnitrosamine (DMN)-induced liver fibrosis in rats and molecular mechanisms underlying prevention of liver fibrosis. Methods: Eighteen Sprague-Dawley rats were divided into three groups of six rats each, liver fibrosis was induced by DMN injection (10 mg kg−1 , ip, given three consecutive days each week) following 4 weeks. YGJ was oral administered (1.8 g kg−1 , op, daily for two weeks). Liver sample were subjected to histological and western bolt studies. For evaluation of hepatic fibrosis-related factors, collagen a1-I, tissue inhibitor of metalloproteinase-1 (TIMP-1), and a-smooth muscle actin (a-SMA) mRNA and protein levels were analyzed. The signaling of associated mechanisms were validated in vitro using HSC-T6 cell lines. Results: YGJ significantly attenuated the DMN-induced excessive level of GOT and GPT (p < 0.01) in serum, and hydroxyproline content in liver tissue (p < 0.001). Histophathological result revealed that YGJ markedly reduced collagen acumination and hepatic satellite cells activation. In gene expression analysis, YGJ down regulated fibrosis-related genes including TIMP-1, collagen a1-I and a-SMA in liver tissue. In protein level, YGJ reduced the a-SMA in liver tissue (p < 0.001). YGJ induced HSCs apoptosis concomitant with the down-regulation of Bcl-2 expression and slight elevation of Bax level. Moreover, the reactive oxygen species (ROS) were generated in the early stages of YGJ-induced HSCs apoptosis to facilitate calcium and cytochrome c release from the mitochondria to cytosol. Subsequently, caspase-9 and caspase-3 were activated. YGJ decoction induces HSCs apoptosis through ROS accumulation and the intrinsic apoptosis pathway. Conclusions: These results showed that YGJ has hepatoprotective and antihepatofibrotic effects against DMN-induced liver fibrosis. Its possible mechanisms are associated with HSCs apoptosis through ROS accumulation and down-regulation of the fibrogenic gene, especially TIMP-1, collagen a1-I and a-SMA.
594 THE EFFECT OF LITHIUM ON CARDIOVASCULAR SYMPTOMS IN CHOLESTATIC RATS A.R. Dehpour1 , M. Rahimi Balaei1 , R. Babaeikelishomi2 , S. Ejtemaei Mehr1 . 1 Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; 2 Department of Molecular Pharmacology, School of Medicine, University of Goettingen, Goettingen, Germany E-mail: [email protected] Background and Aims: Cholestatic liver disease is known for cardiac and renal complications. Short term (10 days) bile duct ligation (BDL) is a model for cholestasis studies. Lithium is widely used for treatment of neuropsychiatric symptoms in bipolar disorders. Recent studies indicate the cardioprotective effects of lithium in heart ischemia-reperfusion and anthracycline-induced injuries. The purpose of this study was to investigate lithium protective effect on heart in BDL rat model of cardiomyopathy. Methods: Male Wistar rats (200–230 g) were chosen and randomized in five groups; control, Li, Li+sham, BDL, Li+BDL. In Li+BDL group, they were treated with 300 mg/kg p.o. lithium in their water supply for three weeks and then for ten days after bile duct ligation. At the end of the experiment, ECG parameters and papillary muscle contractility force were assessed. Serum samples were collected for measurement of lithium concentrations. In addition, cardiac tissues were evaluated both macroscopically and microscopically. Results: We found that lithium can improve bradycardia induced in BDL rats, Sa -T segment, QT interval prolongations and heart contractility force. Also histopatologic findings showed lower cardiac lesions in Li+BDL group (by p < 0.05). Conclusion: All of these findings underline the protective effect of lithium in 10 days BDL rats. 595 BENEFICIAL EFFECT OF N-ACETYL-CYSTEINE ON HEPATIC ENCEPHALOPATHY: “IN VIVO” AND “IN VITRO” STUDY A. Dibenedetto1 , D. Donnini1 , L. Domenis1 , D. De Silvestri1 , D. Cappello1 , A. Carnelutti1 , L. Veriello2 , G. Pauletto2 , L. Sechi1 , G. Soardo1 . 1 Liver Unit, Department of Pathology and Experimental and Clinic Medicine, 2 Neurology Clinic, Department of Pathology and Experimental and Clinic Medicine, University of Udine, Udine, Italy E-mail: [email protected] Introduction: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome which causes severe morbidity in end-stage liver disease. Evidence identifies ammonia as the key factor in the pathogenesis of HE. Experimental animal models has been demonstrated that oxidative/nitrosative stress induces or aggravates astrocyte swelling with subsequent alterations of ammonia metabolism and glioneuronal communication. Aim of study: investigating the potential neuroprotective effects of antioxidant substance such as N-Acetylcysteine (NAC) on ecephalopathy status in a group of cirrhotic patients affected by recurrent episodes of HE and in “in vitro” system of U-87 astrocytes cell line, stimulated with ammonia. Methods: 15 encephalophatic cirrhotic patients (mean age 61.1 y) were studied. 10 patients were treated with conventional therapy plus 2,400 mg/day of NAC. 5 patients were a control group. At the time 0 and 30 we measured ammonia, oxidative stress markers levels: Nitric Oxide (NO), Malondyaldeide (MDA), Glutathione (GSH) and psychometric tests; serial-dotting-test (SDT), trail-making-test A and B (TMT-A, TMT-B). Astrocytes were incubated for 2 hours in absence or in presence of 5 mM of ammonia (NH4 ) with 0.2 mM of Gglutamate and with or without 5 mM of NAC and 2 mM of GSH. As markers of oxidative stress we measured the MDA extra-cellular levels.
Journal of Hepatology 2011 vol. 54 | S209–S361
S241